A portable apparatus for temporarily warming a plurality of vehicle engines includes a warm fluid circulation loop; an engine fluid circulation loop; a fluid heater; a fluid to fluid heat exchangers; a warm fluid pump; and an engine fluid pump. The warm fluid circulation loop connects the warm fluid heater to the fluid to fluid heat exchanger. The engine fluid circulation loop transfers engine fluid from engine fluid systems to the fluid to fluid heat exchanger. The fluid heater heats the fluid in the warm fluid circulation loop and the warm fluid is then circulated through the warm fluid circulation loop to the fluid to fluid heat exchanger to warm the engine fluid in the engine fluid circulation loop. The warmed engine fluid circulates through the engine fluid system warming the vehicle engine. The apparatus is configured to warm a plurality of vehicle engines at the same time.